Update to .NET Standard 2.0

[lucasdm07]

Good evening, I would like to suggest that this package be updated to .NET Standard version 2.0 for greater compatibility with the new versions of .NET

[rigazilla]

Hi @lucasdm07 thanks for the feedback.

Targeting netstandard2.0 would be a nice to have, but I don't know if code and dependencies comply with it.
We're currently working on other project and we're short on time, so I can't plan this task in the near future.

Contributions are always welcome anyway: so if you have time and will to create a PR I'll be happy to review it :)